American geneticist Howard Jacob has glimpsed the future. Without medical motivation, he has had his genome sequenced and now carries his genetic profile around with him via an app on his tablet.

''Within a decade this is going to be common,'' Professor Jacob said. ''And if you want to get the most bang for your buck, you'd do it on the day that a baby is born.''

Genomics involves the study of the genome: the body's genetic blueprint. How a genome is assembled is different for every person.

After having his genome sequenced last year, Professor Jacob learnt of the genetic quirks that lurked in his family tree, including a predisposition to breast cancer for his female relatives.

Advertisement

The genetics field is developing so rapidly that, like any other app on his tablet, Professor Jacobs needs to update the data.

On Wednesday, not long after arriving in Melbourne from Wisconsin, he learnt he was susceptible to Creutzfeldt-Jakob disease.

It sounds grim, but for Professor Jacob the information is empowering. It allows problems to be tackled before they arrive and for lifestyle choices to be made to reduce risk.

He also points out that the presence of a genetic variation doesn't guarantee a disease will develop.

In the case of breast cancer, if the two known genes associated with the disease are identified, it means the carrier of the genes has an 85 per cent chance of developing the condition.

He argues that sequencing the genome of newborns should become standard practice because genetic disorders tend to show up early in life.

When symptoms of a rare disorder present themselves, doctors can't always make a quick diagnosis and this can lead to years of invasive testing for the patient. In the case of one of Professor Jacob's patients, Lillian Yuska, a mystery illness meant six years of tests and scans.

As a last resort, she had her genome sequenced. That revealed a mutation associated with an extremely rare genetic condition known as tricho-hepato-enteric syndrome.

It's so rare that Lillian is the only child in the US with the condition.

''It gave the parents and the family answers and it meant that, at last, we could treat her, knowing what her condition was,'' he said. ''It's what we call personalised medicine.''

In Melbourne as a guest of the Australian Regenerative Medicine Institute this week, Professor Jacob argues that gene sequencing should not be seen as a last resort, but the starting point.

As more people have their genome sequenced, he believes the price will come down, aided by advances in technology and computing power.

Currently it costs about $17,500 - a vast improvement on the $1 billion price tag a decade ago.

Increasingly, genome sequencing is being used as a tool for diagnosis and treatment.

Clarification: The previous version of this story said that Creutzfeldt-Jakob disease is sometimes known as mad cow disease. It is variant, not classical, CJD that is linked to mad cow disease.